A research tool is described for studying the effects of glottal‐pulse waveform on the speech signal. The system is based on a line analog synthesizer program which uses an on‐line glottal‐pulse‐waveform editor. This system allows specification of an arbitrary waveform, which is then taken as the source impulse to synthesize up to 1.5 sec of speech. This new tool has been used for generation of stimuli for listening experiments on glottal source effects.